Rotary impact type screw driver



Oct. 3, 1950 G. w. ALLEN ROTARY IMPACT TYPE SCREW DRIVER Filed March 13. 1947 Fig.2.

Fig.. l.

Inventor George W Allen WWW/g 5MM atenteci ct.

UNITED STATES PATENT orifice ROTARY IMPACT TYPE SCREW DRIVER George W. Allen, Erving, Mass. Application March 13, 1947, Serial No. 734,503

l rlhe present invention relates to new and useful. improvements in screw drivers and equivalent bit-type tools and has more particular reference to means attached to the handle equipped end of a screw driver shank for building up and transmitting extra force such as is often necessary in both seating and unseating screws.

The principal object of the invention is to provide hand-held hammer-driven mechanical means embodying co-acting cams, the latter serving to convert reciprocatory motion into rotary motion suil'lcient to turn a screw in the de- .sired direction.

Needless to say, the art to which the invention relates is characterized by screw drivers having structural adaptations destined to accomplish the aforementioned results. tion in hand, I have evolved and produced what isbelieved to be a novel and improved choice and coordination of parts with a view toward providing a better and more satisfactory screw driver construction.

In carrying out theprinciples of the invention a structural arrangement is had which is simple and practical, easy and eflicient to handle, and otherwise aptly devised to better accomplish the desired ends.

Other objects and advantages of the invention will become more readily apparent from the following description and the accompanying illustrative drawings.

In the drawings, wherein like numerals are employed to designate like` parts throughout the views:

Figure 1 is a view, partly in section and partly in elevation, showing a screw driver constructed in accordance with the particular principles of the instant invention;

Figure 2 is a view, also in section and elevation, based on Figure 1 and of a fragmentary type showing the cams in a relation different from that illustrated in Figure 1;

Figure 3 is a cross section on the line 3-3 of Figure 2, looking in the direction of the arrows.

By way of introduction to the detailed description and briefly summarized, it will be seen that the invention, somewhat specifically considered, is characterized by an elongated hollow handle of cylindrical cross section, said handle having one end closed and adapted to be struck with a mallet or the like, a i'lrst sleeve closed on one end firmly secured into said handle with said closed end abutting the closed end of the handle, a second sleeve secured to said handleand having a reduced end portion rigidly attached to the other Having such informa- '1 Claim. (c1. 145-50) end of said iirst sleevefthe other end portion of said second sleeve (at the end opposite said reduced portion) lying in a plane extending atan acute angle with respect to the longitudinal axis of the handle to forni a cam surface, a shank rotatable and slidable in said second sleeve, said shank having a screwdriver bit at one end and a head at the other end, said head being of greater diameter than the diameter oi the bore in said second sleeve, said headed end being situated in the bore in said rst sleeve and having end in thrust Contact with the closed end of said first sleeve when the shank is in its innermost position, a third sleeve iirmly fixed on said shank I between said second sleeve and the open end of the handle, the end surface of said third sleeve opposed to the inst-mentioned cam surface lyling in a plane extending at substantially the same angle as the first-mentioned cam surface toV provide a second cam surface to coact with said first cam surface to impart rotation to said third sleeve and shank relative to said handle upon relative longitudinal movement of said shank and handle, the open end of said handle having an insert secured therein, said insert having a bore to slidably receive said shank.

Referring now to the drawings by distinguishing reference numerals the shank of the screw driver is denoted by the numeral 5 and the bit by the numeral 6. The upper end of the shank is provided with an assembling impact receptive head l. Spaced inwardly, or downwardly, from the head 'l is a sleeve 8. This is xed on the shank and has its upper end provided with an inclined plane 9, functioning as a cam. For convenience, this part 8 may be identified as the shank rotating anvil. The handle means, generally denoted by the numeral le, is slidable and rotatable in respect to the shank and sleeve and comprises a cylindrical jacket or casing ll which completely houses the anvil 8. A closing plug I2 is secured in the lower end of said handle. A cap-shaped insert or sleeve i3 is press-iitted in the upper end of said handle and is provided with a recess or cavity lll to accommodate the head l. The outer end portion of the handle is enlarged to form a head l5 which may be identined as an impact receiving element. This is adapted to be struck with a hammer, mallet or the like. A third metal or equivalent sleeve I6 is provided and has a reduced end portion I 6*1 which fits into the recess and is welded or otherwise flxedly mounted in place in the bore or recess of said second-named sleeve i3. 'I'he lower surface of the sleeve i6 is also formed with an means, as an individual device, provides not only y a hand-grip and bearing for the shank 5, but also a driver for the driven element or sleeve 8. n

Novelty is predicated on the sleeve means made up of the two sleeves I3 and IG- which are'rigidly connected together with the sleeve IB serving as a bearing or bushing for the turnable and slidable shank 5 and with the recessed portion of the sleeve I3 serving to house the headed end 'I of the shank 5. The closed end of the sleeve I3 serves to impart the desired impact action from .I`5'to I3 to 'I. With the head I1 of a diameter greater than the diameter of the bore in the sleeve J8, it is evident that by removing the plug or insert i2 from the handle I I, the entire assemblage may be withdrawn from the handle. That is to say, the head Il then comes to end-thrust contact with the feature Ia making it possible to pull all three sleeves with the shank 5 in a single operation.

It is understood that a screw driver constructed in; accordance with the special handle means herein shown and described is useful in providing that extra twist or turn which is often so essential in handling screws, that is of the customary type wherein the head of the screw is provided with ia kerf or bit-receiving nick. For instance, if' a screw is rusty and so lodged in place that it may not be started and loosened by hand, using the ordinary screw driver, this improved screw driver will serve to start the screw for removal purposes.

' By the same token, if, in driving the screw home,

an eXtra added turn or two is required to completely sink same, this improved screw driver will accomplish the desired results. In using it, a hammer or mallet is employed and the cams 9 and II are so arranged that by striking a blow '.'against the impact head I5, the handle means ID reciprocates along the shank 5, causing thev cams `@fand I'I, when they have been prearranged, to

provide the rotary movement of the shank 5. Or,

- to put vit otherwise, the drive and driven means 8 and It convert, through inclined companion planes 9 and Il, reciprocatory motion into rotary motion in an obvious manner.

yA careful consideration of the foregoing description in conjunction with the invention as illustrated in the drawings will enable the reader to obtain a clear understanding and impression of the alleged features of merit and novelty suiiicient to clarify the construction of the invention as hereinafter claimed.

Minor changes in shape, size, materials and rearrangement of parts may be resorted to in actual practice so long as no departure is made from the invention as claimed.

I claim: I

A screwdriver of the impact type shown and described comprising an elongated hollow handle of cylindrical cross-section, said handle having one end closed and adapted to be struck with a mallet or the like, a first sleeve closed on one end rmly secured into said handle with said closed end abutting the closed end of the handle, a second sleeve secured to said handle and having lone end portion rigidly attached to the other end shank having a screwdriver bit at one end and a head at the other end, said head being of greater diameter than the diameter of the bore in said second sleeve, said headed end being situated in the bore in said rstsleeve and having end-thrust contact with the 'closed end of said first sleeve when the shank is in its innermost position, a third sleeve firmly fixed on said shank between saids'econdj sleeve and the open end of the handle, the end surface of said third sleeve opposed to the first-mentioned cam'surface lying in a plane extendingatY substantially the same angle as the rst-mentioned` cam'Y surface to provide a second cam surface to coact with said rst cam surface to impart-rotation to 'said'third sleeve and shank vrrelative' Vto" said handle upon relative longitudinal movement of said shank and handle, the open end of said handle having an insert secured therein, said insert having a bore to slidably receive said shank.

' GEORGE W. ALLEN.

REFERENCES CITED The following references are of record in the le of thisY patent:

UNITED STATS PATENTS 

